Kinetic study for the development of an accelerated oxidative stability test to estimate virgin olive oil potential shelf life

Abstract

AbstractThis study proposes an accelerated test performed at mild temperature (40–60 °C) to measure oxidative stability and estimate the potential shelf life of extra‐virgin olive oil (EVOO). The kinetic behavior of normalized oxidation indices (PV, K232 and K270) and the oxidizing substrate [unsaturated fatty acids (UFA)] during storage of different virgin olive oil samples in darkness and at different temperatures (25–60 °C) is reported for the first time. PV and K232 followed an apparent pseudo zero‐order kinetics (R2 >0.951) at all the experimental temperatures in all samples, whereas the evolution of K270 apparently better fitted a pseudo first‐order kinetics (R2 >0.926). The temperature‐dependent kinetics of the oxidation indices and the UFA were well described by the linear Arrhenius equation between 25 and 60 °C (0.960< R2 <0.999, p <0.05). The best correlation between loss of PUFA and increase of oxidation product indices was K232 (0.581< R2 <0.924). The time required to reach the upper limits for PV, K232 and K270 established for the EVOO category in the current EU legislation correlated well with temperature using a potential equation, making it possible to set up an accelerated stability test at temperatures below 60 °C to estimate the potential shelf life under normal storage temperature conditions.